The BMW X4 comes in two basic guises: X4 xDrive28i and X4 xDrive35i. The xDrive28i is powered by a turbocharged 2.0L 4-cylinder engine that produces 240 hp, while the xDrive35i utilizes a twin turbocharged 3.0L 6-cylinder engine producing 300 hp. In both cases, power is sent to all four wheels via an 8-speed automatic transmission. The X4 further sets its self apart from the X3 with a unique interior featuring very nice materials and high quality construction throughout. The ride height is lower than in the X3 and it offers drivers a more classically coupe-like view throughout the greenhouse. Handling has been improved over the X3 as well, with the X4 doing a passable impersonation of a sports car on winding roads, thanks to a lower ride height and more aggressively tuned suspension. The X4 comes nicely equipped with both xDrive28i and xDrive35i versions getting a nearly identical set of amenities. Standard equipment includes 18-inch wheels, 8-way power adjustable front seats, a walnut trimmed interior, a powered glass moonroof, a powered tailgate, rear parking sensors, rain sensing wipers, dynamic cruise control and a 9-speaker stereo with satellite radio. There are two optional packages available on both xDrive28i and xDrive35i models, dubbed M Sport and xLine. Both packages significantly change the exterior of the X4, with the M Sport line deleting various chrome bits and adding more aggressive, body colored exterior enhancements. The M Sport line also includes unique 19-inch wheels and a few interior styling tweaks. The xLine takes the standard X4 in the opposite direction, adding rugged looking exterior enhancements as well as its own set of 19-inch wheels. Safety is enhanced by a full complement of electronic aids as well as by several airbags. Other safety features include a hill start function as well as a mode for descending slippery slopes.